	* {
	  margin: 0;
	  padding: 0;
	}

	body {
	  background-color: #DCDFE6;
	}

	p {
	  width: 400px;
	  height: 400px;
	  border: 10px solid white;
	  margin: 100px auto;
	  position: relative;
	}

	p img {
	  width: 400px;
	  height: 400px;
	}

	p:after {
	  /* 伪类 :after 和 content:""; display:block;组合使用 */
	  content: "";
	  display: block;
	  width: 200px;
	  height: 200px;
	  background-color: rgba(0, 0, 0, .4);
	  position: absolute;
	  bottom: 10px;
	  right: 15px;
	  box-shadow: 0px 30px 20px rgba(0, 0, 0, .4);
	  /* 盒子阴影 */
	  transform: skewY(10deg);
	  z-index: -1;
	}

	p:before {
	  /* 伪类 :before 和 content:""; display:block;组合使用 */
	  content: "";
	  display: block;
	  width: 200px;
	  height: 200px;
	  background-color: rgba(0, 0, 0, .4);
	  position: absolute;
	  bottom: 10px;
	  left: 15px;
	  box-shadow: 0px 30px 20px rgba(0, 0, 0, .4);
	  /* 盒子阴影 */
	  transform: skewY(-10deg);
	  z-index: -1;
	}